The present invention relates to the art of patient aid and invalid care devices. It finds particular application in conjunction with releasing swing-away arm rests and will be described with particular reference thereto. It is to be appreciated, however, that the present invention is also applicable to releasing catches and locks on crutches, commodes, walkers, other parts of wheelchairs, and other patient aids.
Heretofore, many patient aids have been constructed of tubular materials. Adjustable and removable parts commonly interengage telescopically. The telescopically received tubing had a pair or series of matching holes through which a locking detent could selectively pass. When the detent extended through the apertures of both tubes, the tubes were locked against telescopically sliding movement. By pressing the detent with a thumb or finger below the level of the outer tubing, the blocking interaction of the detent was defeated and the tubes could be moved slidably relative to each other.
One of the problems with the spring biased detents is that their operation requires a relatively high degree of manual dexterity. Quadraplegics, the elderly, and other patients frequently lacked sufficient dexterity or finger strength to release the detents. These patients commonly required assistance to remove the removable arms of wheelchairs and make other spring biased detent adjustments.
To accommodate those with less manual dexterity or finger strength, other types of latches were developed. In one example, the detent was replaced with a pin that was pulled outward by a large handle, rather than pushed inward to release the lock. Others used a more elaborate lock in which a large slide member caused a locking pin to retract and extend. As another example, a pivotally mounted member selectively pivoted between a locking and releasing position. Although these other locks were operable with less manual dexterity, they had several other drawbacks. First, these locks were relatively expensive to manufacture and difficult to repair. Further, these release mechanisms had to be factory installed and could not be used to replace the prior art spring detents on existing equipment.
The present invention contemplates a new and improved lock release system which overcomes the above referenced problems and others.